And now Ezra Klein points out it's even going to be worse, because of the timing. Basically, if we end up having a debt ceiling fight in early 2013, it would imply that the fiscal cliff issues that come up in December 2012 weren't solved.

Here's Ezra:

That is to say, it's a scenario in which we've already reached the fiscal cliff and fallen over the edge. It's a scenario in which the Bush tax cuts have probably expired, and the spending cuts have probably begun. It's a scenario in which the markets are already in some amount of turmoil, and the forecasters are already sharply warning that Congress is dragging the country into a double-dip recession. It's a scenario in which the two parties are already under tremendous pressure, in which Washington has been in some sort of semi-crisis for months, and in which all the possible deals have already been tried and failed. (It's also a scenario, incidentally, in which our projected deficits are much lower, because our expected tax revenues are so much higher.)

So basically: Debt ceiling + more acrimony than last time + fiscal-cliffmageddon.